Electric fastening tool



Um. 17, 1967 N. R. DOHERTY ELECTRIC FASTENING TOOL 5 Sheet -Sheet 2Filed Nov. 24, 1965 INVENTOR. NORMAN R. DOHERTY 2 ATTORNEY Get. 17, 1967N. R. DOHERTY 3,347,441

ELECTRI C FASTENING TOOL Filed Nov. 24, 1965 5 Sheets-Sheet 3 "'==a%-"-yINVENTOR. FIG 50 NORMAN R. DOHERTY' BY 17/ M M;

ATTORNEY Uct. 17, 1967 N. R. DOHERTY ELECTRIC FASTENING TOOL 5Sheets-Sheet 4 Filed Nov. 24, 1965 INVENTOR. NORMAN R. DOHERTY ATTORNEYcit. 17, 1967 N. R. DOHERTY ELECTRIC FASTENING TOOL Filed Nov. 24, 19655 Sheets-Sheet 5 INVENTOR. NORMAN R. DOHERTY ATTORNEY United StatesPatent C) ce 3,347,441 ELECTRIC FASTENING TOOL Norman R. Doherty,Farmingdale, N.Y., asslgnor to Electric Stapler Corporation Filed Nov.24, 1965, Ser. No. 509,475 12 Claims. (Cl. 227-131) This inventionrelates to a fastener driving tool and more particularly to anelectrically operated staple driving tool having interchangeable meansfor accommodating a fastening means of diverse size and shape.

The prior art contains many examples of powered fastoning tools ofvarious types. Broadly, they may be broken down into two majorcategories, namely, pneumatically and electrically driven tools.Considering first the pneumatically driven tools, it is readily apparentthat there are several deficiencies in the apparatus now on the market.A common characteristic of pneumatically operated staple fasteners isbulkiness, heavy weight and awkwardness to handle. In order to providesufficient driving force, the cylinder and piston must be inordinatelylarge.

Another deficiency of these tools is that both the cylinder and thedriver blade are assembled as an integral, non-separable package.Therefore, if it is ever desired to interchange or use staples ofanother size, the tool must be returned to the factory, taken apartthere and reassembled with the properly sized components.

Another common characteristic of the pneumatically operated tools isthat the driver blade is coaxial with the piston. Therefore, the toolcannot be used in close proximity to an obstruction.

Probably the greatest deficiency of pneumatically operated fasteningtools is that a source of compressed air is an absolute essential. Quitefrequently the compressed air source is not readily available.Therefore, the tool is not completely universal.

Electrically operated fastening devices representing the second majorcategory suffer at least some of these as well as other deficiencies.First, the power package, usually in the form of a solenoid, has had tobe excessively large in order to deliver sufiicient power to drive theblade and the staples. Concurrent with the large solenoid size is a highpower requirement resulting in an excessive heat output. As with thepneumatically operated tools, the conventional electrically drivenstapler has the driver blade positioned coaxially with the armature ofthe solenoid. Once again the operator cannot work too closely to anobstruction.

The electrically operated tools of the prior art were generally bulky,heavy and awkward to handle. Further, they did not readily adaptthemselves to interchageability. That is, staples having differentwidths, lengths or gauge wire could not easily be used in one gun. Ithas also been found that the electrically operated solenoids of theprior art were relatively slow in operation. That is, staples could notbe fired with any great rapidity. This resulted in a tendency for thestaplers to jam when the operator tried to drive them in too fastsuccession.

By way of contrast, the present invention is lightweight and readilyportable, thereby providing substantially increased utility. Thesolenoid utilized in the present invention is substantially improvedover similar devices used in the prior art. Overheating of a solenoid isprevented thus assuring a longer and more useful life for the presentinvention. This also permits the stapler to be fired repetitively forlong periods of time. A particularly noteworthy feature of the presentinvention is the mounting of the driver blade. Means are provided tomake the driver blade removable from the linearly movable solenoidarmature. The driver blade is mounted in a cantilevered fashion off toone side of the solenoid. Only the 3,347,441 Patented Oct. 17, 1967thickness of the metal housing stands between the driver blade and anyobstruction near which the operator may have to Work.

Another major feature of the instant invention is the completeinterchangeability of the driver blade, the staple supply magazine andthe head housing. The present construction fills a long recognized needfor a single, basic gun that will accommodate a wide range of staplesizes. By changing the staple supply magazine and the driver blade, notonly can different gauge wire staples be used, but staples havingdifferent length legs and different spacings transversely between thelegs can be fired.

In contrast to the prior art, the structure to be described hereinaftercomprises a housing having a permanently mounted power package in theform of a solenoid, rectifier-SCR package and switch means to energizethe solenoid. The stapler driving blade, as well as the combinationstaple magazine and head housing, is readily removable without the useof separable fasteners such as nuts, bolts, rivets and the like. Nospecial tools and no special skills are required to effect theinterchangeability. Moreover, there is no dang-er involved of damagingthe tool or hurting the assembler as there may be with some of the priorart devices. A minimum of time and effort is required to change thestaple sizes, since the blade and the magazine are not secured byseparable fasteners.

The present invention will be described in connection with means fordriving wire staples. More particularly, the structure of an improvedsolenoid will be described as will a novel staple supply and drivingstructure that may be readily removed as complete and self-containedunits from the power portion of the tool and be interchanged withsimilarly functioning but differently sized structures. It is also to beunderstood that the basic concept of this invention may be applied tostaple clinching as well as staple tacking devices, and, in addition, totools for driving other fasteners, such as nails, brads, tacks, pins andthe like.

Accordingly, it is an object of the present invention to provide animproved, lightweight, hand-held, electrically driven staple fasteningtool.

It is another object to provide improved actuating means for the drivingblade of an electrically powered fastening tool.

It is another object to provide an improved solenoid for an electricallypowered fastening tool.

A feature of the present invention driving blade is mounted in acantilevered relationship with respect to the driving blade actuatingmeans.

Yet another object of the present invention is to provide anelectrically driven fastening tool having the driving blade positionedas close to the front of the housing as possible.

A particular feature of this invention is the inclusion, in anelectrically actuated fastening tool, of a driving blade removablylinked to a solenoid armature having an elongated, coaxial bearingadapted to slidably receive the solenoid armature.

It is also an object of this invention to electrically actuated fastenercentrally positioned bearing armature.

Still another object of the present invention is to provide an improvedelectrically operated tool that is usable with fasteners having a widerange of widths.

Yet another object is to provide structure in the aforementioned toolwhereby the fastener supply magazine and the fastener driving blade arereadily separable from the housing containing the power package and thesolenoid armature, respectively.

It is a further feature of this invention to provide an improvedelectric stapler or tacker capable of accommois that the stapleprovide,in an driving tool, an elongated for the axially slidable 3 dating awiderange of interchangeable driver blades and supply magazines.

Still another feature is to provide the aforementionedinterchangeability without recourse to the usual hardware, such asscrews, nuts, rivets or threaded fasteners of any type.

A particular object of this invention is to provide a removable fastenersupply magazine having an integral driver blade guide track for theaforementioned tool.

A further object is to provide low cost yet rugged driver blades andsupply magazines that may be interchangeably used with a single basictool having a self contained power package.

Yet another feature of the present invention is the fact that the powerpackage, which represents the most expensive portion of the tool, iscommon to a wide range of supply magazines in driver blades.

It is still another feature of this invention to provide a single powerpackage and housing, together with a set or range of driver blades andsupply magazines, the total cost for which is far less than the priorart devices having a comparable range.

These and other features, objects and advantages of the invention will,in part, be pointed out with particularity and will, in part, becomeobvious from the following more detailed description of the invention,taken in conjunction with the accompanying drawing, which forms anintegral part thereof.

In the various figures of the drawing like reference charactersdesignate like parts.

In the drawing:

FIG. 1 is a plan view of the present invention;

FIG. 2 is a side elevational view partly in section taken along line 2-2of FIG. 1;

FIG. 3 is a plan view of the solenoid used in the present invention;

FIG. 4 is a sectional side elevational view taken along line 4-4 of FIG.3;

FIG. 5 is a front elevational view of the solenoid with the armature inthe uppermost position;

FIG. 6 is a front elevational view of the solenoid with the armature inthe lowermost position;

FIG. 7 is a pictorial view of the spring clip utilized to hold the majorcomponents of the present invention together;

FIG. 8 is a schematic front view of the range of driver blade widthsavailable for use with the present invention;

FIG. 9 is an exploded side elevational view, partly in section, of thestaple guide track;

FIG. 10 is a sectional plan view taken along line 1010 of FIG. 9;

FIG. 11 is a schematic transverse view of the staple guide trackillustrating the widest staple usable with the present invention;

FIG. 12 is another schematic transverse view of the staple guide trackillustrating the narrowest staple that may be used with this invention;

FIG. 13 is a pictorial view of a staple pusher bar;

FIG. 14 is an exploded side elevational view of the major assembliescomprising the present invention;

FIG. 15 is a schematic drawing of the circuit used in the presentinvention.

Referring now to the drawings and in particular to FIG. 1 and FIG. 2,there is shown an improved, electrically powered fastening toolcomprising the present invention. For the purpose of this descriptionthe apparatus will be broken down into several major components.

I. Housing The housing, in the embodiment illustrated, is formed in twohalves 22a and 22b. The front portion 24 of the combined housing halvesis substantially cylindrical in shape while the mid-portion 26 of thehousing defines a hand-gripping area. Rear portion 23 admits the linecord 30 which is adapted to be connected to a suitable source ofelectrical power. The housing halves are held together by a number ofscrews 32 which pass through clearance holes in one part of the housingand are threadably engaged in the opposite side of the housing.

As may be seen in FIG. 2, the conductors of the line cord are connectedto an electronic package 34 described more fully hereinafter inconjunction with the circuit drawing of FIG. 15.

A snap action type switch 44; for example, the type made by CherryElectric Product Corporation under Catalog No. E34, is suitably securedto the housing in midportion 26, such that the contact button thereofextends downwardly into the hand-gripping opening. Trigger 46 ispivotally mounted just below the switch contact button and is providedwith an actuating member 48 resiliently biased by spring number 50. Anupward force on the trigger closes or opens the contacts of the switch,depending on the particular circuit employed; i.e., actuated by makingor breaking a circuit.

Solenoid 52 is mounted in the forward section of the housing just aheadof the switch member. The solenoid case is comprised of a cylindrical,ferromagnetic, lower section 54 and upper section 56. In the embodimentillustrated, the wire coils 58 and 60, connected in parallel, aredisposed in the base section. Ferromagnetic cover member 62, whichretains the coils in place, is provided with a circular flange portion64 of substantially the same diameter as the outside diameter of thelower section of the solenoid housing. The central bore 66 of the covermember is made with substantially the same diameter as that of thelinearly movable solenoid armature but with sufficient clearance so thatthe armature moves freely therethrough.

Upper ferromagnetic case section 56 is also cylindrical and seats on theupper surface of a cover member flange portion 64. The upper casesection is provided with elongated slots 70 on each side thereof and asingle elongated slot 72 in the front. The purpose of these slots willbe made evident hereinafter. The construction of the solenoid case justdescribed is by way of illustration only, it being understood that thecase sections may be fabricated as a single, drawn piece.

A non-magnetic shaft 76, having a head end 78 seated above the top endof the solenoid case and a threaded lower end 80 passing through thewire coils and the lower section of the solenoid housing, slidinglysupports solenoid armature 82. Central bore 84 of the armature isprovided with an elongated sleeve bearing 86, preferably a porous,magnetizable material having an iron content of the order of 85%. Thisprovides free sliding linear movement of the armature with respect tothe shaft. The upper end of the armature is provided with a flangeportion and a resilient annular member 90.

The lower portion of the solenoid case has welded thereto a strap 92.One of the screws that hold the housing halves together passes throughan aperture in the strap so that the solenoid may be securely held inthe housing. Bracket 94, which will be described hereinafter more fullyin connection with the interchangeability of the supply magazine, isheld on the top of the solenoid housing by the central non-magneticshaft 76. This bracket is provided on the righthand end thereof with atab member 96 that keys into an aperture 98 in the upper solenoidhousing. The righthand end of the bracket is also provided with anaperture through which another of the housing connecting screws pass.Thus, it will be seen that the solenoid, by means of the two housingscrews, is securely held and is unlikely to be vibrated loose. Bracket98, having an arcuate, grooved crown 100, is secured to bracket 94 bymeans of several screws 95. An extensible coil spring 102 is disposed inthe crown groove, such that the ends thereof may be secured to tabs 104on either side of the armature. Spring 102 returns and holds thearmature in its original upward position after the completion of thedownward stroke. The slots in the opposed sides of the solenoid caseprovide clearance for the movement of the solenoid tabs. The springarrangement is an improvement over the use of a compression spring aboutthe central shaft 76 which would prevent the use of the long bearingemployed in this design. Finally, a blade driver pin 106 is providedintegrally with the upper end of the solenoid armature and substantiallyat a right angle thereto. Slot 72 in the front of the solenoid housingprovides clearance for the movement of the blade driver pin.

II. Driver blade Driver blade 110 is provided at its upper end with anaperture 112 so that it may be loosely supported on the drive pin of thesolenoid armature. The driver blade, which may be a metal stamping,forging, etc., is also provided with a pair of spaced, parallel, sideflanges 114 and an arcuate central portion 116, which serve to stiffenthe blade. With the blade mounted on the armature driver pin, thearcuate central portion of the blade is disposed in an arcuate notch orcutout 120 of bracket 94. The fiat lower end 111 of the blade ispositioned over the forwardrnost staple. For different gauge staplesdifferent thickness blades could be interchanged. The range of driverblades that may be utilized with the present invention is schematicallyshown in FIG. 8. The largest width blade is called out as D; thesmallest width blade is called out as D; all the blade widths in betweenthe smallest and the largest are represented as D".

The solenoid case is secured to an elongated upwardly facing channelmember 122 by means of a nut 123 Welded thereto. The central shaftmember 76 of the solenoid is threadably engaged in the nut. At thelefthand end of the channel member, as may be seen in FIG. 2, thesolenoid housing is seated in a notch 124 in each of the legs of thechannel member. The lefthand end of each leg of the channel member isalso provided with a notch 126 to receive the spring clip that holds theseveral major components of the tool together. This will be described indetail subsequently.

To the right of the solenoid the channel member is provided with atransverse pin 128, having laterally extending ends, while at therighthand end of the channel member a second pin 131) is securedtransversely. One end of the linkage 132 is mounted on the secondtransverse pin, while the opposite end of the linkage has an aperturethat receives one of the screws holding the two housing halves together.Another function of the second pin, which also has laterally extendingends, will be described in conjunction with the interchangeability ofthe staple supply magazine. Finally, a leaf spring 134 is rigidlysecured to the forward end of the channel, such that it bears againstthe rearward surface of the driver blade. The function of the springmember is to urge the driver blade forward against the inside surface ofthe head housing in a manner to be described more fully hereinafter.

III. Staple supply magazine and blade guide track A particular featureof the present invention is the use of a one-piece, combination staplesupply magazine and head housing 144] which is removably attached to theremainder of the tool without conventional fasteners. The staple supplymagazine portion is comprised of an upwardly facing channel member 142having a horizontal notch 144 formed in each of the side walls thereofat the righthand end. Notches 144 are adapted to receive the laterallyextending ends of the transverse pin 130 provided at the righthand endof channel member 122. A second upwardly facing notch 146 is formed ineach of the side walls of channel member 142 proximate the midpointthereof, such that they mate with the laterally extending ends of pin128 of channel member 122. A third notch 148 is formed at the lefthandend of channel member 142 in order to receive the transverse portion ofthe clip member that holds the components of the tool together. Notches148 are in registry with notches 126 formed in the channel member 122.

In the assembled condition, pin 128, which is disposed in the notches atthe midportion of the channel member, prevents any longitudinal movementof the magazine with respect to the housing. Finally, a pair oflaterally extending ears 152 are formed by bending over the top edges ofchannel member 142 just rearward of notches 148 and forward of notches146. In the assembled condition notches 148, ears 152 and the laterallyextending ends of the midportion pin 128 cooperate with the means forretaining all the components. The manner in which this is done will beexplained more fully hereinafter.

An elongated rectangular bar 154 is secured to the base wall of channelmember 142. In the embodiment illustrated, a plurality of screws 156perform this function although the bar and channel may be welded. To aidin the accurate positioning of the central bar, pins 157 are asoincluded to act as locating means. The bar 154 is spaced from the sidewalls of channel member 142 to define guide tracks for the parallel legsof the staple. The bar is also spaced from the upwardly facing channelmember that supports the solenoid in order to provide clearance for thetransverse leg of the staple. Staple pusher bar 160, as may best be seenin FIG. 12, is comprised of a downwardly facing channel 162 havingflanges 164 extending transversely from either side at the righthand endthereof. Elongated rods 166 are each slida bly seated in apertures inthe flanges and each rod has positioned thereabout a coil spring 168.The righthand end of the rods are joined by transverse member 170,arranged to fit into a transverse notch 172 in the bar member 154 whenthe pusher bar is disposed in the staple supply magazine. The parallelspring member urges the stick of downwardly facing U-shaped staplestowards the forward end of the tool.

The staples S are adhesively secured together and have a width dimensionsubstantially the same as the width of the bar member on which theyride. The staple stick is limited in its upward movement by channelmember 122. It should be noted at this time that the side walls ofchannel member 142, the top surface of bar 154, and the transverse webof channel 122 are spaced from each other by a dimension sufiicient toform a guide track for accepting the legs and the transverse sectionsrespectively of the staple stick.

The head housing or blade guide means is formed by an upstandingL-shaped channel 172 having spaced side walls 174 straddlingly securedto the outer surfaces of the side walls of channel member 142 at theforward end thereof. Transverse wall 176 of the head housing representsthe forwardmost point of the tool. A die block 180 is also included andis spaced from the inside surface of the transverse wall of the headhousing to provide passage for the staples. For different gauge staplesthe die block would, of course, be positioned differently to provide theappropriate spacing between itself and the inner surface of thetransverse head housing wall. Thus, a range of staple gauges may beaccepted by providing a number of supply magazines having differentlypositioned die blocks.

It is to be understood, of course, that a suitable driver blade would beselected for each staple gauge. Regardless of the width of the blade atthe bottom, the blade flanges 114 are guided in their vertical movementby the spaced side walls 174 of the head housing. The upper ends of theside walls of the head housing are also provided with tabs 186 arrangedto engage notches 1-88 in bracket 94 when the magazine is assembled tothe tool housing. The function of the tabs and the notches will bedescribed subsequently in conjunction with the means to retain thevarious parts locked together.

FIG. 11 and FIG. 12 are transverse sections through typical staplesupply magazines and differ only in the width of the staples theyaccommodate. Taking the extreme sizes, the magazine in FIG. 11 willaccept a staple S having transverse spacing A between the legs thereof.The magazine of FIG. 12 would accept a staple S having a transversedimension between the legs of A. In either case, the spaced parallellegs of the staple are close to, or perhaps only slightly larger than,the width of the bar member secured to the channel of the supplymagazine. A stick of staples is disposed in the guide track defined bythe space between the upstanding walls of the channel member and thesides of the bar. The driver blade D and D that would most efiectivelybe used with staples S and respectively, are schematically shownsuperimposed thereabove. I

It should be noted that only the bar member need be changed fordifferent width staples. By leaving the channel member 142 constant, thetabs in the upper portions of the head housing side walls will mate witha single or constant width bracket 94 secured to the solenoid.Similarly, only the lower staple-engaging portion of the blade need bealtered to correspond with the width of the staple being used. In thisconnection it should be noted that for any staple of lighter gauge thanthe maximum permitted suitable filler members are provided in betweenthe die block and the inside surface of the upper channel. This assuresthat the driver blade, which is suitably dimensioned for each staplesize, is accurately guided throughout its entire travel.

IV. Means to releasably secure the components A single resilient springclip 200 is all that is required to hold the components in the assembledcondition. Finger pressure applied to the ends 202 of the clip on eitherside of the tool housing is all that is needed to release the clip. Inthis manner the combination staple supply magazine and blade guide trackis easily released from the housing and the driver blade is easilyremoved from the solenoid. It is obvious, then, that no screws, bolts,nuts, rivets or similar fasteners are required to hold the majorcomponents together. In fact, no tools or any special skills of any sortare needed. Further, the resiliency of the clip absorbs at least some ofthe shock arising from the driving of each staple and therefore the clipreduces the likelihood of fracturing any of the stapler parts.

Referring in detail now to FIG. 7, spring clip 200 is seen to comprise acentral transverse section 204, which is in assembled condition disposedacross channel memher 142 in notch 148. The solenoid, secured over theclip to the channel 122, retains the clip in the channel whereby theclip is very loosely pivotable in the spaced notches 126 and notches148. Parallel leg members 206 of the clip member extends from each endof tranverse section 204 and are provided with extensions 208 formed atan angle to the legs. The extensions terminate in the finger-grippingportions 202. It will be seen that when portions 202 are snapped overthe laterally extending ends of pin 128, each junction of the legs andthe extensions are disposed below and bear upwardly with substantialforce against the laterally extending ears 152 formed on channel member142. In this manner the three major elements of the tool are releasablysecured to each other.

V. Assembly and disassembly Reference may be had to FIG. 14 for anunderstanding of the ease and simplicity of disassembling, interchangingand reassembling the major sections of the tool. First, the properdriver blade for the particular gauge and size staples to be used isloosely placed on the cantilevered and outwardly extending driver pinintegral with the solenoid armature. The bottom end of the blade restson the leaf spring 134 secured to channel member 122. Then, with thehousing and power package in one hand and the combination staple supplymagazine and head housing in the other hand, the laterally extendingends of transverse pin 131) are inserted into notches 144. With the pinacting as the pivot point, the magazine and head housing are swungupwardly until tabs 186 in the upper sidewalls of the head housing areseated in spaced notches 188 of the bracket secured to the top of thesolenoid. The ends of pin 128 are thereby seated in notches 146 of thechannel member 142. It should be noted that spring member 134 attachedto the forward end of the channel member 122 bears against the lower endof the driver blade, urging it against the inner surface of the headhousing. In combi: nation, then, the space side walls 174, the insidesurface of the transverse wall 176, and the leaf spring 134 define aguide for the travel blade which is arranged to slide therethrough.

At this point in the assembling of the tool, clip 200 is hangingdownwardly in the registered notches of the channel members. The ends ofthe clip member are then forced over and into engagement with thelaterally extending ends of the midportion pin 128 and the tool is readyfor operation. The procedure for disassembly of the tool is just thereverse of that described for the assembly and is equally as simple. Theend of the clip member are released by finger pressure so that the cliploosely hangs down and the tabs of the head housing are pushed out ofthe solenoid bracket notches. With downward pressure on the top of thehead housing, the pin 130 will thereby be released from the rearwardchannel notches and the magazine and driver blade are available forremoval and interchange with differently sized members that are designedto give optimum performance with different size staples. The staples mayrange upward in width from of an inch.

VI. Circuitry With the trigger switch 44 off, capacitor 212 charges tothe peak positive line voltage through solenoid coils 58 and 60, diode214 and resistor 216. The trigger switch may be closed randomly (by theoperator) at any time during the AC cycle. If the switch should closeduring a positive half cycle of the supply, diode 218 prevents flow ofcurrent until the line reverses polarity. With the line negative, gatecurrent flows from the line through the SCR 226 gate, the switch 44,resistor 220 and diode 218, to charge capacitor 222. Current has to takethis path because diode 224 prevents current flow directly from the linein the reverse direction to the switch. Even although the line isnegative the SCR 226 will trigger as soon as the gate current flows,because the SCRs anode is always forward biased by previously chargedcapacitor 212. With SCR 226 gated on, the discharge time constant of theR-C network (capacitor 212 and resistor 216) and the SCR 226 is longenough to maintain SCR 226 in conduction until the line once morereverses polarity. With the line positive once more, load current isable to flow from the line through the solenoid coils and the stillconducting SCR 226. At the end of this half cycle, when the line goesnegative again, SCR 226 is reverse biased and turns off. For the SCR 226to trigger again two conditions must be satisfied, namely: (1) Capacitor212 must be recharged, which requires at least one cycle off time; and(2) Capacitor 212 must be discharged, so that gate current is able toflow again. These conditions can only be satisfied if the switch isreleased for at least one full cycle of the line. This feature precludesmisfiring due to contact bounce.

The advantages and features of the present invention may be summarizedas follows:

(1) The entire structure is compact, rugged and easy to handle.

(2) All of the individual components are easy to manufacture andassemble, so that the cost of the tool is kept low.

(3) The power package and housing, which represent 9 inexpensive supplymagazines and driver blades covering a range of sizes. At a minimum ofcost the user has an entire set of staplers.

(4) No special tool or skill is required to change the device for usewith different sized staples.

(5) When the apparatus is changed for different sized staple sizes, thepower package need not be disturbed by inexperienced personnel. Only thehead housing, the staple supply magazine and the driver blade areremoved with the power package remaining in the housing.

(6) The blade guide or head housing is integral with the removablestaple supply magazine.

(7) The tool housing and power package can accept a range of differentwidth staple supply magazines and driver blades.

(8) Because of the simplicity of this assembly, a jammed staple can beremoved very easily.

(9) Because the driver blade is loosely mounted and so easy to remove, adamaged or worn blade can be replaced without completely dismantling thetool or returning it to the factory.

(10) The principles of the present invention may be used to drivestaples having a straight transverse section or staples having offsetportions in the transverse section.

(11) The tool can be used to drive a variety of different fasteners,such as staples, pins, brads, nails, etc.

(12) The solenoid is provided with an extremely long bearing, thusassuring a perfectly linear travel thereof.

(13) The return spring for the solenoid armature is external of thecase, thus permitting a maximum length bearing for the armature.

(14) The flanges on the driver blade provide a very rugged constructionthat will assure a long life for the tool.

(15) The construction of the housing assures comfortable handling of thetool with the major portion of the weight at the forward end in a mostuseful and comfortable position.

(16) Servicing and assembly of the tool is extremely simple since only afew screws hold the two housing halves together.

While the present invention is primarily concerned with means forinterchangeably accepting different width staples, it should be evidentthat secondary features are also available. Thus, by providing a rangeof magazines, with differently dimensioned die blocks and guide bars,many gauges of staples could be used with a single tool and powerpackage. Further, by making the guide bar of different heights, stapleshaving different length legs could also be used with a single tool.Obviously, then, the interchangeable features of the present inventionprovide that almost any combination of staple width, gauge or length ofleg can be used. The improved solenoid assures long life and ease ofoperation with a minimum of heat being generated. The solenoid furtherprovides sufiicient power to drive a wide range of fastener sizes.

Having thus disclosed the best embodiment of the invention presentlycontemplated, it is to be understood that various changes andmodifications may be made by those skilled in the art without departingfrom the spirit of the invention.

What is claimed is:

1. An electrically powered tool for driving any one of a plurality offasteners having unlike configurations into a workpiece, said toolhaving interchangeable components of the type described, said toolcomprising:

(a) a housing open along the length of the bottom thereof and along atleast a portion of the front thereof;

(b) a solenoid assembly comprised of a casing having a slot therein, awound coil having a central bore and a magnetizable armature linearlymovable through the bore of said coil, said solenoid being securedwithin said housing with a portion of said 10 armature extendingoutwardly through the slot of said casing;

(c) elongated spring means having a portion fixed relative to saidcasing and at least one free end secured to said armature externally ofsaid casing, said spring means being arranged to return said armature toits original position at the end of each stroke;

(d) a trigger carried by said housing;

(e) switch means contained in said housing in electrical connection withsaid solenoid, said trigger being arranged to actuate said switch meanswhereby said solenoid is energized;

(f) a fastener driver blade loosely secured to the externally extendingportion of said armature for movement together therewith, said driverblade being disposed on the outside of said solenoid casing for movementin a plane parallel to that of said armature;

(g) a combination head and fastener supply housing removably mounted onsaid housing in covering relationship to the open front and bottomsurfaces, respectively, thereof, the head portion of said combinationhousing defining a guide track for said driver blade, the fastenersupply portion of said combination housing defining a guide track forthe fasteners to be driven;

(h) a fastener pusher bar slidingly disposed in the fastener supplyportion of said combination housing; and

(i) retaining means to releasably hold said combination housing on saidtool housing.

2. The apparatus in accordance with claim 1 wherein said housing iscomprised of two concave mating sections joined along a common,longitudinal central axis, said forward portion being hollow and shapedto receive said solenoid and said driver blade, said hand-grippingportion being hollow and shaped to receive said switch means, saidforward portion and said rearward portion being spaced from each otherto define a finger opening in combination with said hand-grippingportion, said trigger being postioned in the finger opening whereby,when the user holds the hand-gripping portion, one of the users fingerswill engage said trigger.

3. The apparatus in accordance with claim 1 wherein said solenoidarmature includes an elongated central bore and an elongated hollowbearing integrally secured therein, said solenoid further including acentral shaft extending therethrough and arranged to slidingly supportsaid armature bearing.

4. The apparatus in accordance with claim '3 wherein said bearing issubstantially the same length as said solenoid armature.

5. The apparatus in accordance with claim 3 wherein said bearing ismagnetizable material.

6. The apparatus in accordance with claim 3 wherein said bearing is aporous, magnetizable material comprised predominantly of iron.

7. The apparatus in accordance with claim 1 wherein there is included abracket integrally secured to the top of said solenoid casing, saidbracket having an arcuate, annular groove spanning said solenoid casing,wherein said casing includes a pair of opposed side notches formed inthe wall thereof, wherein said armature includes a pair of opposed tabsand wherein the ends of said spring means are secured to said armaturetabs and the midportion of said spring means is seated in the annulargroove of said bracket.

8. The apparatus in accordance with claim 1 wherein there is included alatching member positioned on the top said solenoid, said latchingmember having a radially extending portion provided with a pair ofnotches, the head portion of said combination head fastener supplyhousing including a pair of spaced ears arranged to releasably interfitwith the notches of said latching member when said tool is assembled.

9. The apparatus in accordance with claim 8 wherein said solenoid casingis provided with a keyway and said latching member includes a keyengaged in said keyway.

10. The apparatus in accordance with claim 1 including a second springmember positioned between said solenoid casing and said driver blade,said second spring member being arranged to urge the lower portion ofsaid driver blade towards the forward end of said tool.

11. The apparatus in accordance with claim 1 wherein said fastenersupply housing is comprised of an elongated U-shaped channel and anelongated, centrally located bar secured to the transverse leg of saidchannel.

12. The apparatus in accordance with claim 1 wherein said fastenerpusher bar is comprised of an inverted U- shaped member having opposed,laterally extending flanges each with an aperture therein, an elongatedrod slidably disposed in each of the apertures in said flanges,

12 a spring member arranged to bias each of said rods with respect tosaid flanges and means to retain said pusher bar in said fastener supplyhousing whereby said U-shaped member urges the fasteners towards theforward end of said tool.

References Cited UNITED STATES PATENTS 2,580,065 12/ 1951 Anstett 227129X 3,037,207 6/1962 Pazan. 3,209,180 9/1965 Doyle.

FOREIGN PATENTS 1,290,830 3/ 1962 France.

GRANVILLE Y. CUSTER, 111., Primary Examiner.

1. AN ELECTRICALLY POWERED TOOL FOR DRIVING ANY ONE OF A PLURALITY OFFASTENERS HAVING UNLIKE CONFIGURATIONS INTO A WORKPIECE, SAID TOOLHAVING INTERCHANGEABLE COMPONENTS OF THE TYPE DESCRIBED, SAID TOOLCOMPRISING: (A) A HOUSING OPEN ALONG THE LENGTH OF THE BOTTOM THEREOFAND ALONG AT LEAST A PORTION OF THE FRONT THEREOF; (B) A SOLENOIDASSEMBLY COMPRISED OF A CASING HAVING A SLOT THEREIN, A WOUND COILHAVING A CENTRAL BORE AND A MAGNETIZABLE ARMATURE LINEARLY MOVABLETHROUGH THE BORE OF SAID COIL, SAID SOLENOID BEING SECURED WITHIN SAIDHOUSING WITH A PORTION OF SAID ARMATURE EXTENDING OUTWARDLY THROUGH THESLOT OF SAID CASING; (C) ELONGATED SPRING MEANS HAVING A PORTION FIXEDRELATIVE TO SAID CASING AND AT LEAST ONE FREE END SECURED TO SAIDARMATURE EXTERNALLY OF SAID CASING, SAID SPRING MEANS BEING ARRANGED TORETURN SAID ARMATURE TO ITS ORIGINAL POSITION AT THE END OF EACH STROKE;(D) A TRIGGER CARRIED BY SAID HOUSING; (E) SWITCH MEANS CONTAINED INSAID HOUSING IN ELECTRICAL CONNECTION WITH SAID SOLENOID, SAID TRIGGERBEING ARRANGED TO ACTUATE SAID SWITCH MEANS WHEREBY SAID SOLENOID ISENERGIZED; (F) A FASTENER DRIVER BLADE LOOSELY SECURED TO THE EXTERNALLYEXTENDING PORTION OF SAID ARMATURE FOR MOVEMENT TOGETHER THEREWITH, SAIDDRIVER BLADE BEING DISPOSED ON THE OUTSIDE OF SAID SOLENOID CASING FORMOVEMENT IN A PLANE PARALLEL TO THAT OF SAID ARMATURE; (G) A COMBINATIONHEAD AND FASTENER SUPPLY HOUSING REMOVABLY MOUNTED ON SAID HOUSING INCOVERING RELATIONSHIP TO THE OPEN FRONT AND BOTTOM SURFACES,RESPECTIVELY, THEREOF, THE HEAD PORTION OF SAID COMBINATION HOUSINGDEFINING A GUIDE TRACK FOR SAID DRIVER BLADE, THE FASTENER SUPPLYPORTION OF SAID COMBINATION HOUSING DEFINING A GUIDE TRACK FOR THEFASTENERS TO BE DRIVEN; (H) A FASTENER PUSHER BAR SLIDINGLY DISPOSED INTHE FASTENER SUPPLY PORTION OF SAID COMBINATION HOUSING AND (I)RETAINING MEANS TO RELEASABLY HOLD SAID COMBINATION HOUSING ON SAID TOOLHOUSING.